This application is based on and claims priority to Japanese Patent Application No. 11-274073, filed Sep. 28, 1999, the entire contents of which is hereby expressly incorporated by reference.
1. Field of the Invention
The present invention relates to a small watercraft, and more particularly to a ventilation system for a small watercraft.
2. Description of Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries a rider and possibly one, two, three or four passengers. A relatively small hull of the personal watercraft commonly defines a riders"" area above an engine compartment. An internal combustion engine frequently powers a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The jet propulsion unit is located within the tunnel and is driven by the engine.
Air ducts typically communicate air into the engine compartment for induction by the engine and to ventilate the engine compartment. Typically, such air ducts are covered by a hatch cover or the like. This arrangement has resulted in problems such as excessive noise generation during air intake, as well as excessive engine noise communicated from the engine compartment to the outside.
A need therefore exists for an improved engine compartment air intake arrangement that reduces noise generated during air intake and that reduces noise communicated from the engine compartment to the outside while providing adequate ventilation of the engine compartment.
In accordance with a first aspect, the present invention includes a watercraft comprising a hull defining an engine compartment, an internal combustion engine located within the engine compartment and having an output shaft, a propulsion device carried by the hull and connected to the engine output shaft, an exhaust system for delivering exhaust gases from the engine to the environment, an air duct extending through the hull and into the engine compartment, and an induction box attached to the hull and enclosing an interior space. The induction box has an opening thereinto and an outer edge that abuts the hull. Also, the induction box is sized such that pressure pulses of air flowing therethrough are dissipated within the box.
In accordance with another aspect of the present invention, a watercraft is provided having a hull defining an engine compartment, an internal combustion engine located within the engine compartment and having an output shaft, a propulsion device carried by the hull and connected to the engine output shaft, an exhaust system for delivering exhaust gases from the engine to the environment, a first and a second air duct extending through the hull and into the engine compartment, a first induction box enclosing a first induction space around the first duct, and a second induction box enclosing a second induction space around the second duct. The first and second air ducts are positioned at substantially the same longitudinal position relative to the hull. Also, the first induction box has a forwardly facing opening, and the second induction box has a rearwardly facing opening.
Further aspects, features, and advantages of the present invention will become apparent from the detailed description of the preferred embodiment which follows.